Diaphragm pump



FIG. 1 is a perspective view of a diaphragm pump showing our new design;

FIG. 2 is a front elevation view thereof;

FIG. 3 is a rear elevation view thereof;

FIG. 4 is a right elevation view thereof;

FIG. 5 is a left elevation view thereof;

FIG. 6 is a top plan view thereof; and,

FIG. 7 is a bottom plan view thereof.

The broken line showing of the ball valve cage in FIG. 5 is for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for a diaphragm pump, as shown and described. 